Sex Pheromone of the Saturniid Moth Hemileuca nevadensis from Southern California.

The major and possibly only component of the sex attractant pheromone of the moth Hemileuca nevadensis (Lepidoptera: Saturniidae) from southern California was determined to be (E10,Z12)-hexadecadienal (E10,Z12-16:Ald). Detectable quantities of the analogs (E10,Z12)-hexadecadien-1-yl acetate (E10,Z12-16:Ac) and (E10,Z12)-hexadecadien-1-ol (E10,Z12-16:OH) were also present in solvent extracts of sex pheromone glands, and stimulated male antennae in coupled gas chromatography-electroantennogram detector (GC-EAD) assays. GC-EAD traces from solid phase microextraction (SPME) wipe samples of sex pheromone glands of calling females confirmed the presence of E10,Z12-16:Ald and traces of E10,Z12-16:OH on the gland surface, but E10,Z12-16:Ac was not detected. Despite evidence for the presence of all three compounds in extracts, behavioral responses to synthetic compounds in the field suggested that only E10,Z12-16:Ald is required for optimal attraction.

A Polyketide Male-Produced Aggregation-Sex Pheromone Shared by the North American Cerambycid Beetle Graphisurus fasciatus and the South American Cerambycid Eutrypanus dorsalis.

The longhorn beetle Graphisurus fasciatus (Degeer) ranges from southeastern Canada to Florida and west to Texas, and has frequently been caught during field trials testing attraction of other cerambycid species to their synthesized pheromones. Collections of headspace volatiles from live beetles revealed that males but not females produce a polyketide compound identified as (4R,6S,7E,9E)-4,6,8-trimethylundeca-7,9-dien-3-one ([4R,6S,7E,9E]-graphisurone). Field trials verified that beetles of both sexes were attracted to the synthesized compound, indicating that it is an aggregation-sex pheromone. This structure represents a new structural motif among cerambycid pheromones, and a new natural product. While this study was in progress, the same compound was isolated from males of the South American cerambycid Eutrypanus dorsalis (Germar), in the same subfamily (Lamiinae) and tribe (Acanthocinini) as G. fasciatus. Field trials in Brazil confirmed that (4R,6S,7E,9E)-graphisurone is also an aggregation-sex pheromone for E. dorsalis, and a possible pheromone for two additional sympatric lamiine species, Hylettus seniculus (Germar) (Acanthocinini) and Oreodera quinquetuberculata (Drapiez) (tribe Acrocinini). These results indicate that graphisurone may be shared among a number of related species, as has been found with many components of cerambycid pheromones.

Identification of a Female-Produced Sex Attractant Pheromone of the Winter Firefly, Photinus corruscus Linnaeus (Coleoptera: Lampyridae).

Firefly flashes are well-known visual signals used by these insects to find, identify, and choose mates. However, many firefly species have lost the ability to produce light as adults. These "unlighted" species generally lack developed adult light organs, are diurnal rather than nocturnal, and are believed to use volatile pheromones acting over a distance to locate mates. While cuticular hydrocarbons, which may function in mate recognition at close range, have been examined for a handful of the over 2000 extant firefly species, no volatile pheromone has ever been identified. In this study, using coupled gas chromatography - electroantennographic detection, we detected a single female-emitted compound that elicited antennal responses from wild-caught male winter fireflies, Photinus corruscus. The compound was identified as (1S)-exo-3-hydroxycamphor (hydroxycamphor). In field trials at two sites across the species' eastern North American range, large numbers of male P. corruscus were attracted to synthesized hydroxycamphor, verifying its function as a volatile sex attractant pheromone. Males spent more time in contact with lures treated with synthesized hydroxycamphor than those treated with solvent only in laboratory two-choice assays. Further, using single sensillum recordings, we characterized a pheromone-sensitive odorant receptor neuron in a specific olfactory sensillum on male P. corruscus antennae and demonstrated its sensitivity to hydroxycamphor. Thus, this study has identified the first volatile pheromone and its corresponding sensory neuron for any firefly species, and provides a tool for monitoring P. corruscus populations for conservation and further inquiry into the chemical and cellular bases for sexual communication among fireflies.

(1R,4R)-Quercivorol, a Male-Produced Aggregation-Sex Pheromone of the Beetle Elytrimitatrix undata (F.) (Coleoptera: Disteniidae).

The beetle family Disteniidae is currently considered to be closely related to the much larger family Cerambycidae, the longhorned beetles. The 300 + species of disteniids are mostly native to tropical and subtropical regions, with the only described North American species north of Mexico being Elytrimitatrix undata (F.). Here we describe the identification and field testing of (1R,4R)-quercivorol as a male-produced aggregation-sex pheromone component for E. undata. This is the first pheromone identified for any species within the family Disteniidae.

Silencing Doublesex expression triggers three-level pheromonal feminization in Nasonia vitripennis males.

Doublesex (Dsx) has a conserved function in controlling sexual morphological differences in insects, but our knowledge of its role in regulating sexual behaviour is primarily limited to Drosophila. Here, we show with the parasitoid wasp Nasonia vitripennis that males whose Dsx gene had been silenced (NvDsx-i) underwent a three-level pheromonal feminization: (i) NvDsx-i males were no longer able to attract females from a distance, owing to drastically reduced titres of the long-range sex pheromone; (ii) NvDsx-i males were courted by wild-type males as though they were females, which correlated with a lower abundance of alkenes in their cuticular hydrocarbon (CHC) profiles. Supplementation with realistic amounts of synthetic (Z)-9-hentriacontene (Z9C31), the most significantly reduced alkene in NvDsx-i males, to NvDsx-i males interrupted courtship by wild-type conspecific males. Supplementation of female CHC profiles with Z9C31 reduced courtship and mating attempts by wild-type males. These results prove that Z9C31 is crucial for sex discrimination in N. vitripennis; and (iii) Nvdsx-i males were hampered in eliciting female receptivity and thus experienced severely reduced mating success, suggesting that they are unable to produce the to-date unidentified oral aphrodisiac pheromone reported in N. vitripennis males. We conclude that Dsx is a multi-level key regulator of pheromone-mediated sexual communication in N. vitripennis.

A Gland of Many Uses: a Diversity of Compounds in the Labial Glands of the Bumble Bee Bombus impatiens Suggests Multiple Signaling Functions.

Communication in social insect colonies depends on signals accurately reflecting the identity and physiological state of the individuals. Such information is coded by the products of multiple exocrine glands, and the resulting blends reflect the species, sex, caste, age, task, reproductive status, and health of an individual, and may also contain caste-specific pheromones regulating the behavior and physiology of other individuals. Here we examined the composition of labial gland secretions in females of the bumble bee Bombus impatiens, of different castes, social condition, age, mating status, and ovarian activation. We show that active queens, gynes, and workers each produce caste-specific compounds that may serve different communicative functions. The composition and amounts of wax esters, mostly octyl esters produced by active queens, differed significantly between castes, mating, and social conditions, suggesting a social signaling role. Farnesyl esters were predominant in gynes and peaked at optimal mating age (6-10 days), suggesting their possible roles as sex pheromone components. Reproductive status of females and age across castes was reflected by the ratio between short- and long-chain hydrocarbons, suggesting that these compounds may serve as fertility signals. Our findings overall suggest that the labial gland composition in B. impatiens reflects different facets of female physiology. While further bioassays are required to determine the functions of these compounds, they are likely to have important roles in communication between individuals.

Characterization of Queen Supergene Pheromone in the Red Imported Fire Ant Using Worker Discrimination Assays.

Ants use chemical signals to communicate for various purposes related to colony function. Social organization in the red imported fire ant, Solenopsis invicta, is determined by the Sb supergene, with colonies of the monogyne (single-queen) form lacking the element and colonies of the polygyne (multiple-queen) form possessing it. Polygyne workers accept new reproductive queens in their nest, but only those carrying Sb; young winged queens lacking this genetic element are executed as they mature sexually in their natal nest or as they attempt to enter a foreign nest to initiate reproduction after mating and shedding their wings. It has been suggested that queen supergene genotype status is signaled to workers by unsaturated cuticular hydrocarbons, while queen reproductive status is signaled by piperidines (venom alkaloids). We used high-throughput behavioral assays to study worker acceptance of paper dummies dosed with fractions of extracts of polygyne queens, or blends of synthetic counterparts of queen cuticular compounds. We show that the queen supergene pheromone comprises a blend of monoene and diene unsaturated hydrocarbons. Our assays also reveal that unsaturated hydrocarbons elicit discrimination by polygyne workers only when associated with additional compounds that signal queen fertility. This synergistic effect was obtained with a polar fraction of queen extracts, but not by the piperidine alkaloids, suggesting that the chemical(s) indicating queen reproductive status are compounds more polar than cuticular hydrocarbons but are not the piperidine alkaloids. Our results advance understanding of the role of chemical signaling that is central to the regulation of social organization in an important invasive pest and model ant species.

A Novel Trisubstituted Tetrahydropyran as a Possible Pheromone Component for the South American Cerambycid Beetle Macropophora accentifer.

A novel trisubstituted tetrahydropyran was isolated and identified from the sex-specific volatiles produced by males of the cerambycid beetle Macropophora accentifer (Olivier), a serious pest of citrus and other fruit crops in South America. The compound was the major component in the headspace volatiles, and it was synthesized in racemic form. However, in field trials, the racemate was only weakly attractive to beetles of both sexes, suggesting that attraction might be inhibited by the presence of the "unnatural" enantiomer in the racemate. Alternatively, the male-produced volatiles contained a number of minor and trace components, including a compound tentatively identified as a homolog of the major component, as well as a number of unsaturated 8-carbon alcohols and aldehydes. Further work is required to conclusively identify and synthesize these minor components, to determine whether one or more of them are crucial components of the active pheromone blend for this species.

Determination of the Absolute Configuration of the Male-Produced Sex Pheromone of the Stink Bug Pellaea stictica, (2R,4R,8R)-2,4,8,13-Tetramethyltetradecan-1-ol by Stereoselective Synthesis Coupled with Enantiomeric Resolution.

In a previous study, we reported the identification and synthesis of a male-specific sex pheromone component of the stink bug, Pellaea stictica, as the alcohol 2,4,8,13-tetramethyltetradecan-1-ol (1). To establish the correlation between the stereochemistry of the pheromone and its bioactivity, it first was necessary to determine its absolute configuration. For this purpose, a series of syntheses were designed to: (a) furnish a mixture of all possible stereoisomers; (b) a narrowed down group of diastereomers, and (c) one specific enantiomer. A crucial step in the syntheses involved a coupling reaction between two key intermediates: a phosphonium salt and an aldehyde, through a Wittig olefination. Nuclear magnetic resonance data of a mixture of the synthetic pheromone diastereomers and further comparison of GC retention times with that of the natural product by gas chromatography suggested that the methyl branches at C2 and C4 were in a syn relationship, reducing the possibilities to only four of the eight possible stereoisomers. Employing GC analysis, chiral derivatization reagents and synthetic (8R)-2,4-syn-1 it was possible to confirm the configuration of the methyl branch at C8 as R, reducing the number of possible stereoisomers to two. After enantioselective synthesis of (2R,4R,8R)-1, the absolute configurations of all methyl branches of the natural compound were confirmed as R, fully identifying the male-produced sex pheromone of P. stictica as (2R,4R,8R)-2,4,8,13-tetramethyltetradecan-1-ol.

Identification and Synthesis of Leptotriene, a Unique Sesquiterpene Hydrocarbon from Males of the Leaffooted Bugs Leptoglossus zonatus and L. occidentalis.

The leaffooted bugs Leptoglossus zonatus and L. occidentalis (Hemiptera: Coreidae) cause substantial damage in tree nut crops in North America and pine seed orchards in North America and Europe, respectively. Sexually mature males of both species produce a number of aldehydes, esters, and sesquiterpenes, which are hypothesized to constitute an aggregation pheromone attractive to both sexes. Among the volatiles produced by males of both species, we identified a unique sesquiterpene hydrocarbon, given the common name "leptotriene" (5), which elicited strong responses from antennae of both sexes in electroantennogram assays. Here, we report its structure and its synthesis from (-)-(E)-ß-caryophyllene (1).

A Symmetrical Diester as the Sex Attractant Pheromone of the North American Click Beetle Parallelostethus attenuatus (Say) (Coleoptera: Elateridae).

Hexanoic acid, 1-octanol, 1,8-octanediol, octyl hexanoate, 1,8-octanediol monohexanoate, and 1,8-octanediol dihexanoate were identified in headspace volatiles collected from the crushed abdomen of a female click beetle of the species Parallelostethus attenuatus (Say) (Elaterinae, tribe Elaterini). In field trials carried out in Illinois, South Carolina, North Carolina, and Virginia, adult male beetles were strongly attracted to 1,8-octanediol dihexanoate alone. Blends of the dihexanoate with one or more of the other compounds proved to be less attractive than the dihexanoate alone, suggesting that the pheromone of this species may consist of a single compound. The symmetrical diester structure of the pheromone is a novel natural product and appears to be structurally unique among insect pheromones.

Methionol, a Sulfur-Containing Pheromone Component from the North American Cerambycid Beetle Knulliana cincta cincta.

We describe the identification and field testing of 3-methylthiopropan-1-ol (methionol) as a male-produced aggregation-sex pheromone for the cerambycid beetle Knulliana cincta cincta (Drury) (subfamily Cerambycinae, tribe Bothriospilini). The corresponding sulfoxide, 3-methylsulfinylpropan-1-ol, was also produced sex-specifically by males, but its function remains unclear because the measured release rates of this compound from five different types of release devices were very low to undetectable. Unexpectedly, adults of the cerambycine Elaphidion mucronatum (Say) (Elaphidiini), primarily females, also were attracted by methionol, despite males of this species producing an aggregation-sex pheromone of entirely different structure, (2E,6Z,9Z)-2,6,9-pentadecatrienal.

Phylogeography of an endemic California silkmoth genus suggests the importance of an unheralded central California province in generating regional endemic biodiversity.

The California Floristic province is a biodiversity hotspot. Understanding the phylogeographic patterns that exist in this diverse region is essential to understanding its evolution and for guiding conservation efforts. Calosaturnia is a charismatic silkmoth genus endemic to large portions of the region with three described species, C. mendocino, C. walterorum, and C. albofasciata. We sampled all three species from across their ranges, sequenced 1463 bp of mitochondrial COI and 1941 bp of nuclear DNA from three genes, and reconstructed phylogenetic relationships and estimated divergence times within the lineages. All three species show pronounced evidence of isolation and, in two cases, secondary reconnection. An unexpected monophyletic mtDNA lineage was found in the Central Coast region, in a region thought to represent an intergrade between C. mendocino and C. walterorum. Our genetic data also significantly revise previous hypotheses as to which species occur in which regions, suggesting that historical ecological changes around four Ma ago isolated some lineages, and a secondary isolation event two Ma ago led to isolation of populations both in the Central Coast region and the southern Sierra Nevada. Our results add to a currently under-appreciated pattern suggesting that coastal Central California is not a transition zone between Northern and Southern California Floristic Province faunas but rather its own unique, periodically isolated, biogeographic region. They also suggest cryptic diversity may be present in many other currently unrecognized groups. Additional research should focus on this central California region because many species may be highly restricted in range and in need of conservation attention.

3-Hydroxyhexan-2-one and 3-Methylthiopropan-1-ol as Pheromone Candidates for the South American Cerambycid Beetles Stizocera phtisica and Chydarteres dimidiatus dimidiatus, and Six Related Species.

Here, we study the pheromone chemistry of two South American cerambycid beetle species, and their behavioral responses to candidate pheromone components. Adult males of Stizocera phtisica Gounelle (subfamily Cerambycinae: tribe Elaphidiini) produced a sex-specific blend of (R)-3-hydroxyhexan-2-one with lesser amounts of 3-methylthiopropan-1-ol. In field bioassays, traps baited with racemic 3-hydroxyhexan-2-one and 3-methylthiopropan-1-ol did not catch conspecific beetles, but did catch both sexes of a sympatric species, Chydarteres dimidiatus dimidiatus (F.) (Cerambycinae: Trachyderini). We found that males of this species also produce (R)-3-hydroxyhexan-2-one and 3-methylthiopropan-1-ol, and small amounts of 2-phenylethanol. Subsequent bioassays with these compounds showed that a blend of 3-hydroxyhexan-2-one and 3-methylthiopropan-1-ol constitutes the aggregation-sex pheromone of C. d. dimidiatus, with 2-phenylethanol not influencing the attraction of conspecifics. During the field bioassays, six other species in the Cerambycinae also were caught in significant numbers, including Aglaoschema ventrale (Germar) (tribe Compsocerini), congeners Chrysoprasis aurigena (Germar), Chrysoprasis linearis Bates, and an unidentified Chrysoprasis species (Dichophyiini), and Cotyclytus curvatus (Germar) and Itaclytus olivaceus (Laporte & Gory) (both Clytini), suggesting that one or more of the compounds tested are also pheromone components for these species.

Deceptive signals and behaviors of a cleptoparasitic beetle show local adaptation to different host bee species.

Chemosensory signals play a key role in species recognition and mate location in both invertebrate and vertebrate species. Closely related species often produce similar but distinct signals by varying the ratios or components in pheromone blends to avoid interference in their communication channels and minimize cross-attraction among congeners. However, exploitation of reproductive signals by predators and parasites also may provide strong selective pressure on signal phenotypes. For example, bolas spiders mimic the pheromones of several moth species to attract their prey, and parasitic blister beetle larvae, known as triungulins, cooperatively produce an olfactory signal that mimics the sex pheromone of their female host bees to attract male bees, as the first step in being transported by their hosts to their nests. In both cases, there is strong selection pressure on the host to discriminate real mates from aggressive mimics and, conversely, on the predator, parasite, or parasitoid to track and locally adapt to the evolving signals of its hosts. Here we show local adaptation of a beetle, Meloe franciscanus (Coleoptera: Meloidae), to the pheromone chemistry and mate location behavior of its hosts, two species of solitary bees in the genus Habropoda We report that Mfranciscanus' deceptive signal is locally host-adapted in its chemical composition and ratio of components, with host bees from each allopatric population preferring the deceptive signals of their sympatric parasite population. Furthermore, in different locales, the triungulin aggregations have adapted their perching height to the height at which local male bees typically patrol for females.

Identification of a queen pheromone mediating the rearing of adult sexuals in the pharaoh ant Monomorium pharaonis.

The division of labour between reproductive queens and mostly sterile workers is among the defining characteristics of social insects. Queen-produced chemical signals advertising her presence and fertility status, i.e. queen pheromones, are normally used to assert the queen's reproductive dominance in the colony. Most queen pheromones identified to date are chemicals that stop the daughter workers from reproducing. Nevertheless, it has long been suggested that queen pheromones could also regulate reproduction in different ways. In some multiple-queen ants with obligately sterile workers, for example-such as fire ants and pharaoh ants-queen pheromones are thought to regulate reproduction by inhibiting the rearing of new sexuals. Here, we identify the first such queen pheromone in the pharaoh ant Monomorium pharaonis and demonstrate its mode of action via bioassays with the pure biosynthesized compound. In particular, we show that the monocyclic diterpene neocembrene, which in different Monomorium species is produced solely by fertile, egg-laying queens, strongly inhibits the rearing of new sexuals (queens and males) and also exerts a weakly attractive 'queen retinue' effect on the workers. This is the first time that a queen pheromone with such a dual function has been identified in a social insect species with obligately sterile workers.

Sex Attractant Pheromone of the Japanese Slave-Making Ant, Polyergus samurai.

The objective of our project was to identify the sex attractant pheromone of queens of the slave-making ant Polyergus samurai, which was characterized as a blend of methyl 6-methylsalicylate and methyl 3-ethyl-4-methylpentanoate. Both compounds were identified in volatiles collected from squashed heads of queens, and in field trials, a blend of the two compounds was highly attractive to males. In contrast, males were not attracted to a blend of methyl 6-methylsalicylate with 3-ethyl-4-methylpentanol. Thus, the pheromone blend of this species is analogous to that of species in the Polyergus lucidus complex from eastern North America, rather than that of the Polyergus breviceps complex from western North America and the European species P. rufescens. These results are discussed in the context of speciation within the genus.

Female-Produced Sex Pheromone of Tetrastichus planipennisi, a Parasitoid Introduced for Biological Control of the Invasive Emerald Ash Borer, Agrilus planipennis.

The Asian eulophid wasp Tetrastichus planipennisi is being released in North America as a biocontrol agent for the emerald ash borer (Agrilus planipennis), a very destructive invasive buprestid beetle that is devastating ash trees (Fraxinus spp.). We identified, synthesized, and tested a female-produced sex pheromone for the wasp. The key component eliciting behavioral responses from male wasps in flight tunnel bioassays was identified as (6S,10S)-(2E,4E,8E)-4,6,8,10-tetramethyltrideca-2,4,8-triene. Female specificity was demonstrated by gas chromatographic (GC) comparison of male and female volatile emissions and whole body extracts. The identification was aided by coupled gas chromatography/mass spectrometry analysis, microchemical reactions, NMR, GC analyses with a chiral stationary phase column, and matching GC retention times and mass spectra with those of synthetic standards. The tetramethyl-triene hydrocarbon was synthesized as a mixture of two enantiomeric pairs of diastereomers, and as the pure insect-produced stereoisomer. In flight-tunnel bioassays, males responded to both the natural pheromone and the chiral synthetic material by upwind flight and landing on the source. In contrast, the mixture of four stereoisomers was not attractive, indicating that one or more of the "unnatural" stereoisomers antagonized attraction. Field trials, using yellow pan traps baited with natural pheromone, captured significantly more male wasps than control traps over a four week trial. The identified pheromone could increase the efficiency and specificity of the current detection methods for Tetrastichus planipennisi and aid in the determination of parasitoid establishment at release sites.

Pheromone Composition and Chemical Ecology of Six Species of Cerambycid Beetles in the Subfamily Lamiinae.

Cerambycid beetles of the subfamily Lamiinae use male-produced aggregation-sex pheromones that are attractive to both sexes. Terpenoid pheromones have been identified from species in the tribes Acanthoderini and Acanthocinini native to North and South America, comprised of (E)-6,10-dimethyl-5,9-undecadien-2-one (geranylacetone), the structurally related 6-methylhept-5-en-2-one (sulcatone), and/or specific enantiomers or nonracemic ratios of enantiomers of the related compounds (E)-6,10-dimethyl-5,9-undecadien-2-ol (fuscumol), its acetate ester, (E)-6,10-dimethyl-5,9-undecadien-2-yl acetate (fuscumol acetate), and 6-methylhept-5-en-2-ol (sulcatol). Here, we present new information about the chemical ecology of six acanthoderine and acanthocinine species native to the eastern USA. The pheromone of Astyleiopus variegatus (Haldeman) previously was identified as a blend of (S)-fuscumol and (S)-fuscumol acetate, and we report here that geranylacetone is a synergistic component. Males of Aegomorphus modestus (Gyllenhal), Lepturges angulatus (LeConte), and Lepturges confluens (Haldeman) were found to produce similar blends composed of the enantiomers of fuscumol acetate and geranylacetone, whereas males of Astylidius parvus (LeConte) and Sternidius alpha (Say) produced both enantiomers of fuscumol together with (R)-fuscumol acetate and geranylacetone. Field experiments with synthesized chemicals revealed that species with similar pheromone composition nevertheless differed in their responses to individual components, and to various blends of components, and in how attraction was influenced by chemicals that were pheromone components of other species. Sulcatone and/or sulcatol antagonized attraction of some species to pheromones of the geranylacetone class, suggesting that there is an adaptive advantage in an ability to detect these heterospecific compounds, such as in avoiding cross attraction to other cerambycid species, as yet unknown, that use pheromones composed of both chemical classes.

Factors Associated with Variation in Cuticular Hydrocarbon Profiles in the Navel Orangeworm, Amyelois transitella (Lepidoptera: Pyralidae).

Cuticular hydrocarbons (CHCs) are the main components of the epicuticular wax layer that in many insects functions as a barrier against desiccation. CHCs also play many other roles, including serving as sex pheromones, kairomones, primer pheromones, and colony-, caste-, species- and sex-recognition signals. In insects, CHC profiles can vary depending upon age, species, sex, and strain. Understanding factors associated with variation in hydrocarbon profiles is important for identifying potential vulnerabilities relating to pest ecology and life histories and for developing tools for pest monitoring and management strategies. In this study, we assessed potential sources of variation in CHC profiles in the navel orangeworm Amyelois transitella (Walker) (Lepidoptera: Pyralidae), an economically important pest of nut crops in California. Using coupled gas chromatography-mass spectrometry, we characterized and compared CHC profiles between adults of pyrethroid-resistant (R347) and susceptible (ALMOND) strains. We further compared CHC profiles from adults differing in age (1, 3, 5, and 7 d post-eclosion) and sex. Hydrocarbon profiles comprised 47 different CHCs in detectable quantities that ranged from C17 to C43 in chain length and included straight-chain alkanes and a variety of mono-, di-, and tri-methylalkanes. Adults from resistant populations had greater quantities of CHCs in total than those from susceptible strains, but relative quantities of individual components were similar. The six most abundant compounds were n-pentacosane, n-heptacosane, n-nonacosane, n-hentriacontane, 11,25 + 13,23 + 15,21-dimethylpentatriacontane, and 13,23 + 11,25 + 9,17-dimethylheptatriacontane. Post-eclosion, total CHCs increased with adult age, with males producing greater quantities than females at all ages. Our results show that CHC profiles vary depending on age, sex, and strain and suggest that CHC profiles may be useful as biomarkers to differentiate between insecticide- resistant and susceptible populations.